1. Field of the invention
The present invention relates to a device for dispensing optical fibers in helical grooves of a ring, intended for obtaining an optical fiber cable in a cabling line. The ring is drawn along the cabling line and runs in particular through a rotating holder carrying spools that pay out optical fibers towards fiber-guides in the dispensing device in which the fibers are lodged in the ring grooves prior to taping of the ring to hold the fibers in the grooves.
More particularly, the invention deals with a device for dispensing optical fibers in helical grooves of a ring comprising a holder rotating about the ring and including conduits each containing a hollow fiber-guide receiving at least one optical fiber. The fiber-guides are arranged along generating lines of a cone coaxial with the ring and have first fiber-output ends designed to engage in the ring grooves.
2. Description of the prior art
Such optical fiber dispensing devices are disclosed in French patent application No. 2,388,931, European patent application No. 0,003,930, and U.K patent application No. 2,121,209A corresponding to U.S. Pat. No. 4,497,164. The fiber-guides take the form of hollow capillary tubes secured in the fiber-guide holder by bonding in particular. The tubes have an inside diameter approximately equal to that of an optical fiber. The tubes are often clogged with dust causing an obstacle to optical fiber translation. The first ends of the capillary tubes are relatively resilient and curved in order to enter tangentially the ring grooves. The first ends of the capillary tubes are permanently arranged about a circle having a diameter smaller than the outside diameter of the ring such that the fiber-guide holder rotates about the ring in terms of the sometimes variable pitch of the helical grooves in the ring.
When a ring is red manually into the cabling line prior to any cabling operation as such, the first ends of the tubes must be carefully engaged in the ring grooves. The ring is then drawn for several meters up to a cable winding means at one end of the cabling line, after having run in particular through one or more taping units. The operation of manually drawing the ring requires some considerable effort to overcome the inertia of the fiber-guide holder that is rotationally driven as a result of the translational movement of the ring. Further, while the ring is being fed between the first ends of the fiber-guides and also during the cabling operations, the first ends of the tubes undergo excessive bending that can damage the fibers and adversely affect accurate penetration into the ring grooves.
In addition, the optical fibers unwound from the pay-out spools must be completely clear of the fiber-guides when the ring is fed therebetween. This means that the fibers must be relocated with respect to the ring grooves.
It is worth noting that the dispensing device is not mechanically linked to the fiber pay-out spool holder and is used also for slaving the rotational speed of the spool holder to the pitch of the ring grooves with the help of opto-electronic coupling means. The fiber-guides do not therefore become ideally positioned with respect to the pay-out spools until the cabling operation, and any manual operation or any difference between the rotational speeds of the spool holder and the fiber-guide holder results in undesirable twisting and bending in the fibers.